SNPs in ERCC1, ERCC2, and XRCC1 genes of the DNA repair pathway and risk of male infertility in the Asian populations: association study, meta-analysis, and trial sequential analysis.
ABSTRACT: PURPOSE:We investigated if substitutions in the ERCC1, ERCC2, and XRCC1 genes of the DNA repair pathway correlate with non-obstructive azoospermia and male infertility. METHODS:A total of 548 azoospermic infertile males and 410 fertile controls were genotyped for XRCC1 399A?>?G, 280G?>?A, and ERCC1 C?>?A 3' UTR and 541 azoospermic infertile males and 416 fertile controls were genotyped for ERCC2 751A?>?C using iPLEX Gold Assay. Meta-analyses were performed on XRCC1 399A?>?G (1022 cases and 1004 controls), ERCC1 C?>?A 3' UTR (879 cases and 1059 controls), and ERCC2 751A?>?C (914 cases and 850 controls) polymorphisms to quantitatively estimate the significance of the association between these polymorphisms and the risk of infertility. RESULTS:Statistically significant association between ERCC2 751A?>?C SNP and male infertility was found using the codominant model (p =?0.03). Results of meta-analysis suggested a lack of correlation with male infertility risk, which could be due to pooling of studies from different ethnic populations. Due to limited the number of studies, a stratified analysis for different ethnic groups could not be performed. CONCLUSION (S):In conclusion, AA genotype of 751A?>?C SNP in ERCC2 correlated with a higher risk of male infertility and may contribute to an increased risk of azoospermia and male infertility in Indian men.
Project description:Background and aims:? Azoospermia factor c (AZFc) microdeletions are associated with male infertility and are caused by intrachromosal recombination between homologous repetitive sequence segments. Partial AZFc deletion (gr/gr) has been reported in male factor infertility. In the present study, we established detecting the copy number using quantitative real-time polymerase chain reaction (qRT-PCR) with the genome DNA, and assessed the association of the recombination pair set of gr/gr deletion and deleted in azoospermia copies. Furthermore, we determined the clinical significance of differential recombination patterns of gr/gr deletion, and compared them with azoospermia and proven fertile volunteers, with both groups having gr/gr deleted Japanese subjects. Materials and methods:? A total of 16 Japanese subjects with idiopathic azoospermia, and 13 proven fertile men with gr/gr deletion, were studied. qRT-PCR was used for the estimation of an identical site number. Results:? The g1/g2 deletion was found in 69.2% (9/13) in proven fertile men and in 75% (12/16) of idiopathic infertile men. The gr/gr deletion could result in the recombination of g1/g2 segments. Furthermore, there was no difference in the position of deletion between azoospermic patients and controls (P = 0.59). Conclusion:? There was no association between the loss of DAZ cluster and azoospermia in gr/gr deletion. This suggests that most of the partial deletions are neutral variants.
Project description:The present study determined an association between idiopathic sperm disorders in a local Pakistani infertile male population and the MTHFR C677T polymorphism. After ruling out non genetic factors, a total of 437 idiopathic infertile men including 57 azoospermic, 66 oligospermic, 44 asthenozoospermic, 29 teratozoospermic, 20 oligoasthenospermic and 221 infertile normospermic men were recruited. Furthermore, 218 normospermic fertile men, who had two children (or more) were included as controls. The polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) technique was used to determine MTHFR C677T (rs1801133) polymorphism. A significant association of the minor MTHFR 677T allele with male infertility was observed (p <0.05). In addition, men with MTHFR 677 CT and TT genotypes were at a greater risk [odds ratio (OR): 1.81, 95% confidence interval (95% CI): 1.17-2.80, p = 0.008 and OR: 9.24, 95% CI: 1.20-70.92, p = 0.032, respectively] of infertility. All the subgroups of male infertility (azoospermic, oligospermic, asthenospermic, oligoasthenoteratospermic (OAT) and normospermic infertile) had significantly (p <0.05) higher frequencies of CT and TT genotypes when compared to fertile men. The combined genotypes (CT + TT) were also found significantly (OR: 2.01, 95% CI: 1.31-3.08, p <0.001) associated with male infertility. The results suggest that the polymorphism might be a factor of male infertility in the Pakistani population.
Project description:Although piwi-interacting RNAs (piRNAs) play pivotal roles in spermatogenesis, little is known about piRNAs in the seminal plasma of infertile males. In this study, we systematically investigated the profiles of seminal plasma piRNAs in infertile males to identify piRNAs that are altered during infertility and evaluate their diagnostic value. Seminal plasma samples were obtained from 211 infertile patients (asthenozoospermia and azoospermia) and 91 fertile controls. High-throughput sequencing technology was employed to screen piRNA profiles in seminal plasma samples pooled from healthy controls and infertile patients. The results identified 61 markedly altered piRNAs in infertile patient groups compared with control group. Next, a quantitative RT-PCR assay was conducted in the training and validation sets to measure and confirm the concentrations of altered piRNAs. The results identified a panel of 5 piRNAs that were significantly decreased in seminal plasma of infertile patients compared with healthy controls. ROC curve analysis and risk score analysis revealed that the diagnostic potential of these 5 piRNAs to distinguish asthenozoospermic and azoospermic individuals from healthy controls was high. In summary, this study identifies a panel of piRNAs that can accurately distinguish fertile from infertile males. This finding may provide pathophysiological clues about the development of infertility.
Project description:Deletions in the AZoospermia Factor (AZF) regions (spermatogenesis loci) on the human Y chromosome are reported as one of the most common causes of severe testiculopathy and spermatogenic defects leading to male infertility, yet not much data is available for Indian infertile men. Therefore, we screened for AZF region deletions in 973 infertile men consisting of 771 azoospermia, 105 oligozoospermia and 97 oligoteratozoospermia cases, along with 587 fertile normozoospermic men. The deletion screening was carried out using AZF-specific markers: STSs (Sequence Tagged Sites), SNVs (Single Nucleotide Variations), PCR-RFLP (Polymerase Chain Reaction - Restriction Fragment Length Polymorphism) analysis of STS amplicons, DNA sequencing and Southern hybridization techniques. Our study revealed deletion events in a total of 29.4% of infertile Indian men. Of these, non-allelic homologous recombination (NAHR) events accounted for 25.8%, which included 3.5% AZFb deletions, 2.3% AZFbc deletions, 6.9% complete AZFc deletions, and 13.1% partial AZFc deletions. We observed 3.2% AZFa deletions and a rare long AZFabc region deletion in 0.5% azoospermic men. This study illustrates how the ethnicity, endogamy and long-time geographical isolation of Indian populations might have played a major role in the high frequencies of deletion events.
Project description:<h4>Objective</h4>To determine whether men with azoospermia are at an elevated risk of developing cancer in the years following an infertility evaluation.<h4>Design</h4>Cohort study.<h4>Setting</h4>United States andrology clinic.<h4>Patient(s)</h4>A total of 2,238 men with complete records were evaluated for infertility at a single andrology clinic in Texas from 1989 to 2009.<h4>Intervention(s)</h4>None.<h4>Main outcome measure(s)</h4>Cancer incidence was determined by linkage to the Texas Cancer Registry.<h4>Result(s)</h4>In all, 451 men had azoospermia, and 1,787 were not azoospermic, with a mean age at infertility evaluation of 35.7 years. Compared with the general population, infertile men had a higher risk of cancer, with 29 cases observed compared with 16.7 expected (standardized incidence rate [SIR] 1.7, 95% confidence interval [CI] 1.2-2.5). When stratifying by azoospermia status, azoospermic men had an elevated risk of cancer (SIR 2.9, 95% CI 1.4-5.4). Infertile men without azoospermia had a trend toward a higher rate of cancer (SIR 1.4, 95% CI 0.9-2.2). The Cox regression model revealed that azoospermic men had 2.2-fold higher cancer risk compared with nonazoospermic men (hazard ratio 2.2, 95% CI 1.0-4.8).<h4>Conclusion(s)</h4>Men with azoospermia have an increased risk of subsequently developing cancer, suggesting a possible common etiology between azoospermia and cancer development. Additional follow-up of azoospermic men after reproductive efforts end may be warranted.
Project description:PURPOSE: The present study is a case-control analysis of a SNP (rs28368082) in exon 7 of the SPO11 gene and its possible association with male infertility in three provinces of Iran. We also searched for genetic differences among populations. METHODS: Using Polymerase Chain Reaction-Restriction Fragment Length Polymorphism (PCR-RFLP) analysis, we genotyped 113 infertile men and 50 fertile controls. Then, samples consisting SNP, as determined by PCR-RFLP, were genotyped by sequencing. The differences in genotype distributions between cases and fertile controls were examined using Chi-squared analysis. The genetic difference between individuals with mutated nucleotide was investigated by phylogenetic trees. Genetic difference among populations (provinces) was analyzed through ANOVA test, and homogeneity was investigated using STRUCTURE and K-means clustering analysis. RESULTS: According to the statistical analysis, the SNP was significantly associated with male infertility in all populations except oligozoospermic cases of the Center region. The phylogenetic trees showed partial genetic variation among the individuals, although ANOVA test showed no significant genetic difference between populations (provinces) for both azoospermic, and oligozoospermic cases. Eventually, we affirmed that individuals in the inclusive populations had genetic difference, but it was not statistically significant for dividing underlying populations to separate groups, so each population was homogenous. CONCLUSION: Our study indicates that the mentioned polymorphism in SPO11 gene may be linked to the susceptibility of azoospermia and oligozoospermia male infertility in three provinces of Iran. Further studies are required to support obtained results. It finally should be noted that the possible association between a particular SNP and a specific disease completely depends on the underlying population.
Project description:STUDY QUESTION:Are exosomal microRNAs (miRNAs) in seminal plasma (SP) useful as markers of the origin of azoospermia and the presence of sperm in the testis? SUMMARY ANSWER:Our study demonstrated the potential of several miRNAs contained in small extracellular vesicles (sEVs) of seminal fluid as sensitive and specific biomarkers for selecting those azoospermic individuals with real chances of obtaining spermatozoa from the testicular biopsy. WHAT IS KNOWN ALREADY:There are no precise non-invasive diagnostic methods for classifying the origin of the sperm defects in semen and the spermatogenic reserve of the testis in those infertile men with a total absence of sperm in the ejaculate (azoospermia). The diagnosis of such individuals is often based on the practice of biopsies. In this context it is reasonable to study the presence of organ-specific markers in human semen that contains fluid from the testis and the male reproductive glands, which could help in the diagnosis and prognosis of male infertility. Additionally, seminal fluid contains high concentrations of sEVs that are morphologically and molecularly consistent with exosomes, which originate from multiple cellular sources in the male reproductive tract. STUDY DESIGN, SIZE, DURATION:A case and control prospective study was performed. This study compares the miRNA content of exosomes in semen samples obtained from nine normozoospermic fertile individuals (control group), 14 infertile men diagnosed with azoospermia due to spermatogenic failure, and 13 individuals with obstructive azoospermia and conserved spermatogenesis. Additionally, three severe oligozoospermic individuals (<5 × 106 sperm/ml) were included in the study. PARTICIPANTS/MATERIALS, SETTING, METHODS:A differential high-throughput miRNA profiling analysis using miRNA quantitative PCR panels was performed in SP exosomes from azoospermic patients and fertile individuals. MAIN RESULTS AND THE ROLE OF CHANCE:A total of 623 miRNAs were included in the miRNA profiling stage of the study. A total of 397 miRNAs (63.7%) were consistently detected in samples from all groups and statistically analysed, which revealed altered patterns of miRNA expression in infertile patients. We focused on the miRNAs that were differentially expressed between azoospermia as a result of an obstruction in the genital tract (i.e. having conserved spermatogenesis) and azoospermia caused by spermatogenic failure, and described, in a miRNA validation stage of the study, the expression values of one miRNA (miR-31-5p) in exosomes from semen as a predictive biomarker test for the origin of azoospermia with high sensitivity and specificity (>90%). The efficacy of the predictive test was even better when the blood FSH values were included in the analysis. Furthermore a model that included miR-539-5p and miR-941 expression values is also described as being useful for predicting the presence of residual spermatogenesis in individuals with severe spermatogenic disorders with diagnostic accuracy. LIMITATIONS, REASONS FOR CAUTION:Further studies, with an independent second population involving a larger number of samples, are needed to confirm our findings. WIDER IMPLICATIONS OF THE FINDINGS:Our findings contribute to the search for the most valuable genetic markers that are potentially useful as tools for predicting the presence of testicular sperm in azoospermic individuals. STUDY FUNDING/COMPETING INTEREST(S):This work was financially supported by grants from the Fondo de Investigaciones Sanitarias/Fondo Europeo de Desarrollo Regional "Una manera de hacer Europa" (FIS/FEDER) [Grant number PI15/00153], the Generalitat de Catalunya [Grant number 2014SGR5412]. S.L. is sponsored by the Researchers Stabilization Program (ISCIII/Generalitat de Catalunya) from the Spanish National Health System [CES09/020].
Project description:Infertility is the inability of a couple to conceive after one and a half years of unprotected sex. Male infertility, which accounts for almost half of infertility cases, is considered as a major problem all over the world. The aim of this study was to investigate the association of CYP1A1 polymorphisms with idiopathic non-obstructive azoospermia in a South Indian cohort.An experimental study was conducted with idiopathic nonobstructive azoospermia. A total of 120 infertile and 80 fertile samples were collected, and DNA was then extracted from all samples. The CYP1A1*2A polymorphism genotyping was carried out by polymerase chain reaction (PCR) and restriction fragment length polymorphism (RFLP).The genotype distribution of CYP1A1*2A polymorphism showed significant difference between patients and controls. Moreover, the CC genotype was associated with decreased risk of idiopathic non-obstructive azoospermia in comparison with the TT and TC genotypes.The current experimental study identified that the CT genotype of CYP1A1*2A polymorphism may contribute to the pathogenesis of male infertility in the South Indian population.
Project description:A recent study found that three recurrent deletions of X chromosome linked copy number variations (CNVs), CNV64, CNV67 and CNV69 were associated with idiopathic male infertility in Spanish and Italian populations, especially CNV67 resembling the azoospermia factor deletions. That merits further investigations among different populations. This study was conducted to examine the prevalence of the three CNVs deletions and their associations with idiopathic male infertility in Chinese Han population. The present study included a large population of 1550 Chinese Han subjects recruited between 2014 and 2016. In total, 714 infertile participants were diagnosed as idiopathic infertility with different conditions (288 with non-obstructive azoospermia, 210 oligozoospermia and 216 asthenospermia) and 836 fertile participants (vasectomized men). The fertile participants were recruited from the representative areas: the north (Hebei and Shanxi), center (Hubei and Jiangsu), and south (Guangdong) of China. All patients were recruited from Hubei province. A multiplex PCR system was established to screen the deletion of the three CNVs, and deletion was confirmed by general PCR. Similar rates of these deletions were observed in infertile men and fertile participants (Hubei), and among the different conditions of infertility. Moreover, CNV64 and CNV67 map distribution geographically differed across China. The three CNVs in fertile groups of other regions were similar, except for Guangdong. No association between the three CNVs deletions and idiopathic male infertility was observed. CNV67 is rare in central China, albeit large sample size study for confirmation is warranted. It seems that the association between these CNVs deletions and idiopathic male infertility is ethnic dependent. There is still need to screen the CNVs deletions in other ethnicities. We suggested to consider the stratification patterns and geographic differences when prescribing CNVs deletions screening as a test in male infertility.
Project description:Background:At present, one out of six couples is infertile, and in 50% of cases, infertility is attributed to male infertility factors. Genetic abnormalities are found in 10%-20% of patients showing severe spermatogenesis disorders, including non-obstructive azoospermia. Methods:Literatures covering the relationship between male infertility and genetic disorders or chromosomal abnormalities were studied and summarized. Main findings Results:Genetic disorders, including Klinefelter syndrome, balanced reciprocal translocation, Robertsonian translocation, structural abnormalities in Y chromosome, XX male, azoospermic factor (AZF) deletions, and congenital bilateral absence of vas deferens were summarized and discussed from a practical point of view. Among them, understanding on AZF deletions significantly changed owing to advanced elucidation of their pathogenesis. Due to its technical progress, AZF deletion test can reveal their delicate variations and predict the condition of spermatogenesis. Thirty-nine candidate genes possibly responsible for azoospermia have been identified in the last 10 years owing to the advances in genome sequencing technologies. Conclusion:Genetic testing for chromosomes and AZF deletions should be examined in cases of severe oligozoospermia and azoospermia. Genetic counseling should be offered before and after genetic testing.